Coating composition



United States Patent Rushton, 3802 S. 5200 West, both of Salt Lake City 15, Utah No Drawing. Filed Apr. 2, 1959, Ser. No. 803,561

9 Claims. (Cl. 106-253) This invention relates to coating materials of the nature of paints, enamels, lacquers, varnishes, and the like, and is concerned with the provision of a new coating composition that is superior in many respects to presently known coating compositions of comparable type. The present application constitutes a continuation-in-part of our copending application Serial Number 514,392 filed June 9, 1955, entitled Paint Composition, and now abandoned.

We have discovered that molybdenite, conveniently in the impure form of metallurgical concentrates as produced by various mining and milling concerns engaged in the processing of low grade copper sulfide ores for the recovery of copper, makes an excellent ingredient for various coating materials which are liquid prior to application and which dry to form protective films.

Many deposits of low grade copper sulfide ore contain a commercially recoverable quantity of mulybdenite, which is a natural molybdenum disulfide. Molybdenite metallurgical concentrates are obtained as a by-product of the metallurgical milling of these ores by flotation for the primary recovery of copper. As such, they are in finely ground condition, intimately intermixed with a minor proportion (approximately 10%) of silica.

While the chemical analysis of such metallurgical concentrates varies somewhat from time to time in any given mill, and as between different mills, the essential characteristics are the same. Such variations as may exist are not detrimental for purposes of the present invention. The requisite constituent, namely, molybdenite, remains by far the greatest from a quantitative standpoint, and is controlling so far as the composition is concerned.

Molybdenite and molybdenite metallurgical concentrates are dark gray in color, have a metallic luster, and are slippery and adherent to the touch. In the latter respect, they somewhat resemble graphite. While the concentrates are usually of sufficiently fine mesh for direct introduction to the liquid vehicle, they may be subjected to further grinding whenever that seems desirable.

Practically any of the usual film forming vehicles can be employed. Linseed oil gives excellent results, but other drying oils, such as tung oil, soybean oil, fish oil, dehydrated castor oil, and other oils customarily used for imparting a tough and waterproof film, may be successfully used. In combination with molybdenite these make excellent paint for all outdoor uses, particularly for roofs, where it is highly resistant to weathering and to the heat and actinic action of intense sunlight.

Other common film-forming vehicles may also be employed, for example, nitrocellulose and cellulose acetate lacquers, varnish, rubber base compositions, organic and inorganic binders, thermal-setting resin lacquers, and various synthetic resin coating compositions, e.g. vinyl, melamine and urea formaldehydes, alkyd, casein, and polyesters. Even though the vehicle may be regarded as ordinarily unsuited for outdoor use, it has 2,956,897 Patented O ct. 18, 1930 regardless of vehicle, is applied to surfaces of metal lines and stacks, which, in use, reach temperatures higher than can be sustained by the vehicle film but below the alteration point of molybdenite.

The molybdenite and molybdenite metallurgical concentrates provide a natural soft gray pigmentation in and of themselves. Other pigments can, however, be added for modifying the natural color, or for producing a variety of other desired colors. Also, other ingredients conventional in the art may be added, for example, thinners, such as turpentine and mineral spirits, dryers, water (where compatible with other ingredients), pigment extenders, and the like, particularly clay as a filler.

In this connection, it should be realized that the silica naturally present in the concentrates functions as a pigment extender, and adds desirable sparkle to the coating.

Paint compositions containing the molybdenite or its metallurgical concentrates have spreading, brushing, and drying characteristics comparable to conventional paints, but are superior to most known paints in their covering power and in their resistance to the weather and to abrasion generally. They exhibit unusual resistance to heat, and are especially valuable for painting smokestacks, flues, and all surfaces exposed to high temperatures, regardless of vehicle.

As mentioned above, the invention is also of particular significance as applied to roof paints. Roof paint compositions containing molybdenite or its metallurgical concentrates as a pigment or filler have proven to adhere tenaciously to red cedar shingles and the like, to Withstand the actinic action and heat of direct sunlight for a considerably longer time than paints ordinarily used for the purpose, and to durably resist weather of all types. Furthermore, they impart fire resistance.

The proportion of molybdenum sulfide metallurgical concentrates used in relation to the other ingredients may be in accordance with standard practice applicable to use of pigments and fillers generally. Where linseed oil is utilized as the vehicle, as it preferably is for most outdoor and special heat resistant use, a very satisfactory paint is prepared by mixing approximately one part by volume of the concentrates with three parts by volume of the linseed oil. These same proportions are also preferred for most purposes where other vehicles are employed.

Whereas this invention is here illustrated and described with respect to specific embodiments thereof, it should be realized that changes may be made within the scope of the following claims, without departing from the essential contributions which we have made to the art.

We claim:

l. A heat and weather resistant paint, consisting of linseed oil, and finely divided molybdenite dispersed therein.

2. The paint of claim 1, wherein there is approximately one part of the molybdenite by volume to approximately three parts of the linseed oil by volume.

3. A heat and weather resistant paint, comprising linseed oil, and molybdenum sulfide metallurgical concentrates consisting essentially of the mineral molybdenite in finely divided condition dispersed therein.

4. The paint of claim 3, wherein there is approximately one part of the concentrates by volume to approximately three parts of the linseed oil by volume.

5. A heat and weather resistant paint, comprising a drying oil as a film-forming ingredient, and molybdenite dispersed therein.

6. A heat and weather resistant paint, comprising a and great covering 7 3 4 v drying oil *as a film-forming ingredient, and molybdenum 9. A coating composition, comprising a filming ve sulfide metallurgical concentrates consisting essentially hicle of drying character, and molybdenum sulfide metalof the mineral molybdenite in finely divided condition lurgical concentrates consisting essentially ofmolybdedispersed therein. nits in finely divided condition dispersed therein.

7.- A. coating composition; comprising a filming ve-- 5 hide of drying character, and finely-divided molybdenite References Cited in the file of this patent dispersed therein.

8. A coating composition consisting essentially of a UNITED STATES PATENTS filming vehicle of drying character, and finely-divided 1,662,741 Gardner Mar. 13, 1928 molybdenite dispersed therein. 10' 2,362,670 Schulze Nov. 14, 1944 

1. A HEAT AND WEATHER RESISTANT PAINT, CONSISTING OF LINSEED OIL, AND FINELY DIVIDED MOLYBDENITE DISPERSED THEREIN. 